/* Estilos base con font-size base de 10px (1rem = 10px) */
html {
    font-size: 62.5%;
    box-sizing: border-box;
}

*, *::before, *::after {
    box-sizing: inherit;
    margin: 0;
    padding: 0;
}

:root {
    /* Paleta de colores azules y fríos */
    --bg-gradient: linear-gradient(135deg, #0b0f19 0%, #111827 50%, #1e1b4b 100%);
    --card-bg: rgba(17, 24, 39, 0.75);
    --card-border: rgba(56, 189, 248, 0.15);
    
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    --color-primary: #38bdf8;       /* Celeste/Sky brillante */
    --color-primary-hover: #0ea5e9; /* Celeste más oscuro */
    --color-primary-light: rgba(56, 189, 248, 0.1);
    
    --color-success: #10b981;       /* Verde para fortaleza alta */
    --color-warning: #f59e0b;       /* Naranja para fortaleza media */
    --color-danger: #ef4444;        /* Rojo para fortaleza baja */
    --color-very-strong: #06b6d4;   /* Turquesa para fortaleza extrema */
    --color-neutral-bar: #374151;   /* Gris para barra vacía */
    
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    
    --shadow-premium: 0 2rem 4rem rgba(0, 0, 0, 0.4), 0 0.5rem 1.5rem rgba(0, 0, 0, 0.2);
    --shadow-glow: 0 0 1.5rem rgba(56, 189, 248, 0.3);
    
    --radius-lg: 1.6rem;
    --radius-md: 1.2rem;
    --radius-sm: 0.8rem;
    
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

body {
    font-family: var(--font-main);
    font-size: 1.6rem; /* 16px */
    background: var(--bg-gradient);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    overflow-x: hidden;
}

/* Contenedor de la Aplicación */
.app-container {
    width: 100%;
    max-width: 50rem;
    display: flex;
    flex-direction: column;
    gap: 3rem;
    animation: fadeIn 0.6s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(2rem);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Header */
.app-header {
    text-align: center;
}

.app-header h1 {
    font-size: 3.2rem;
    font-weight: 700;
    letter-spacing: -0.05em;
    background: linear-gradient(to right, #ffffff, #93c5fd, #38bdf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1rem;
}

.app-subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Tarjeta del Generador (Glassmorphism) */
.generator-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    backdrop-filter: blur(1.6rem);
    -webkit-backdrop-filter: blur(1.6rem);
    border-radius: var(--radius-lg);
    padding: 3rem;
    box-shadow: var(--shadow-premium);
    display: flex;
    flex-direction: column;
    gap: 3rem;
}

/* Sección de Visualización */
.display-section {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid rgba(56, 189, 248, 0.1);
    border-radius: var(--radius-md);
    padding: 0.5rem;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.input-wrapper:focus-within {
    border-color: var(--color-primary);
    box-shadow: 0 0 1.2rem rgba(56, 189, 248, 0.15);
}

#password-display {
    width: 100%;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 2.2rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    padding: 1.2rem 1.5rem;
    text-overflow: ellipsis;
}

#password-display::placeholder {
    color: var(--text-muted);
    font-family: var(--font-main);
    font-size: 1.6rem;
    letter-spacing: 0;
    font-weight: 400;
}

/* Botones de Iconos (Copiar / Ojo) */
.icon-btn {
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 1rem;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color var(--transition-fast), background-color var(--transition-fast), transform var(--transition-fast);
}

.icon-btn:hover {
    color: var(--color-primary);
    background-color: var(--color-primary-light);
}

.icon-btn:active {
    transform: scale(0.95);
}

.icon-btn svg {
    width: 2.2rem;
    height: 2.2rem;
}

.hidden {
    display: none !important;
}

/* Indicador de Fortaleza */
.strength-container {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    padding: 0 0.5rem;
}

.strength-label {
    font-size: 1.3rem;
    color: var(--text-secondary);
}

.strength-label strong {
    font-weight: 600;
    transition: color var(--transition-normal);
}

.strength-bar-wrapper {
    width: 100%;
    height: 0.6rem;
    background: var(--color-neutral-bar);
    border-radius: 0.3rem;
    overflow: hidden;
}

.strength-bar {
    height: 100%;
    width: 0%;
    border-radius: 0.3rem;
    transition: width var(--transition-normal), background-color var(--transition-normal);
}

/* Estados de fortaleza */
.strength-bar.level-0 { width: 0%; background-color: var(--color-neutral-bar); }
.strength-bar.level-1 { width: 25%; background-color: var(--color-danger); }
.strength-bar.level-2 { width: 50%; background-color: var(--color-warning); }
.strength-bar.level-3 { width: 75%; background-color: var(--color-success); }
.strength-bar.level-4 { width: 100%; background-color: var(--color-very-strong); }

#strength-text.level-0 { color: var(--text-muted); }
#strength-text.level-1 { color: var(--color-danger); }
#strength-text.level-2 { color: var(--color-warning); }
#strength-text.level-3 { color: var(--color-success); }
#strength-text.level-4 { color: var(--color-very-strong); }

/* Sección de Ajustes */
.settings-section {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
}

/* Slider y Input Numérico */
.setting-group {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.setting-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.setting-header label {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.length-number-input {
    width: 6.5rem;
    background: rgba(15, 23, 42, 0.8);
    border: 1px solid rgba(56, 189, 248, 0.2);
    border-radius: var(--radius-sm);
    color: var(--color-primary);
    font-family: var(--font-mono);
    font-size: 1.6rem;
    font-weight: 600;
    text-align: center;
    padding: 0.6rem 0;
    outline: none;
    -moz-appearance: textfield;
}

.length-number-input::-webkit-outer-spin-button,
.length-number-input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.length-number-input:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 1rem rgba(56, 189, 248, 0.15);
}

.slider-wrapper {
    width: 100%;
    display: flex;
    align-items: center;
}

/* Custom Input Range */
.slider-input {
    -webkit-appearance: none;
    width: 100%;
    height: 0.6rem;
    background: var(--color-neutral-bar);
    border-radius: 0.3rem;
    outline: none;
    cursor: pointer;
}

.slider-input::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 2rem;
    height: 2rem;
    border-radius: 50%;
    background: var(--color-primary);
    box-shadow: 0 0 1rem rgba(56, 189, 248, 0.4);
    transition: transform var(--transition-fast), background-color var(--transition-fast);
}

.slider-input::-webkit-slider-thumb:hover {
    transform: scale(1.15);
    background: var(--text-primary);
}

.slider-input::-webkit-slider-thumb:active {
    transform: scale(0.95);
}

.slider-input::-moz-range-thumb {
    width: 2rem;
    height: 2rem;
    border: none;
    border-radius: 50%;
    background: var(--color-primary);
    box-shadow: 0 0 1rem rgba(56, 189, 248, 0.4);
    transition: transform var(--transition-fast), background-color var(--transition-fast);
    cursor: pointer;
}

.slider-input::-moz-range-thumb:hover {
    transform: scale(1.15);
    background: var(--text-primary);
}

/* Grid de Opciones Checkbox */
.options-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.6rem;
}

.option-item {
    display: flex;
    align-items: center;
}

/* Estilo Checkbox Premium Customizado */
.custom-checkbox {
    display: flex;
    align-items: center;
    position: relative;
    padding-left: 3.5rem;
    cursor: pointer;
    font-size: 1.4rem;
    color: var(--text-secondary);
    user-select: none;
    min-height: 2.4rem;
    transition: color var(--transition-fast);
}

.custom-checkbox:hover {
    color: var(--text-primary);
}

.custom-checkbox input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

.checkmark {
    position: absolute;
    top: 0;
    left: 0;
    height: 2.4rem;
    width: 2.4rem;
    background-color: rgba(15, 23, 42, 0.8);
    border: 1px solid rgba(56, 189, 248, 0.2);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.custom-checkbox:hover input ~ .checkmark {
    border-color: rgba(56, 189, 248, 0.5);
    background-color: rgba(15, 23, 42, 0.9);
}

.custom-checkbox input:checked ~ .checkmark {
    background-color: var(--color-primary-light);
    border-color: var(--color-primary);
    box-shadow: 0 0 0.8rem rgba(56, 189, 248, 0.25);
}

.checkmark::after {
    content: "";
    position: absolute;
    display: none;
}

.custom-checkbox input:checked ~ .checkmark::after {
    display: block;
}

.custom-checkbox .checkmark::after {
    left: 0.8rem;
    top: 0.4rem;
    width: 0.6rem;
    height: 1.2rem;
    border: solid var(--color-primary);
    border-width: 0 0.25rem 0.25rem 0;
    transform: rotate(45deg);
}

.option-label {
    line-height: 1.2;
}

/* Botón Principal (Generar) */
.primary-btn {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-hover) 100%);
    border: none;
    outline: none;
    color: #0b0f19;
    font-family: var(--font-main);
    font-size: 1.6rem;
    font-weight: 600;
    padding: 1.6rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    box-shadow: 0 0.8rem 2rem rgba(56, 189, 248, 0.2);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), filter var(--transition-fast);
}

.primary-btn:hover {
    filter: brightness(1.05);
    box-shadow: 0 0.8rem 2.4rem rgba(56, 189, 248, 0.35), var(--shadow-glow);
}

.primary-btn:active {
    transform: scale(0.98);
}

.btn-icon {
    width: 2rem;
    height: 2rem;
    transition: transform var(--transition-normal);
}

.primary-btn:hover .btn-icon {
    transform: rotate(180deg);
}

/* Footer */
.app-footer {
    text-align: center;
    font-size: 1.2rem;
    color: var(--text-muted);
    line-height: 1.6;
    padding: 0 2rem;
}

/* Contenedor de Notificaciones Toast */
.toast-container {
    position: fixed;
    bottom: 3rem;
    right: 3rem;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
    pointer-events: none;
}

.toast {
    background: rgba(17, 24, 39, 0.9);
    border: 1px solid var(--card-border);
    backdrop-filter: blur(1rem);
    -webkit-backdrop-filter: blur(1rem);
    color: var(--text-primary);
    padding: 1.4rem 2.4rem;
    border-radius: var(--radius-md);
    font-size: 1.4rem;
    font-weight: 500;
    box-shadow: var(--shadow-premium);
    display: flex;
    align-items: center;
    gap: 1rem;
    pointer-events: auto;
    animation: slideIn 0.3s cubic-bezier(0.16, 1, 0.3, 1), fadeOut 0.3s cubic-bezier(0.16, 1, 0.3, 1) 3s forwards;
}

.toast.toast-error {
    border-color: rgba(239, 68, 68, 0.4);
    background: rgba(24, 15, 20, 0.9);
}

.toast.toast-success {
    border-color: rgba(16, 185, 129, 0.4);
    background: rgba(15, 23, 20, 0.9);
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(100%) translateY(0);
    }
    to {
        opacity: 1;
        transform: translateX(0) translateY(0);
    }
}

@keyframes fadeOut {
    from {
        opacity: 1;
        transform: scale(1);
    }
    to {
        opacity: 0;
        transform: scale(0.9);
        display: none;
    }
}

/* Adaptación responsive móvil */
@media (max-width: 480px) {
    body {
        padding: 1.5rem;
    }
    
    .generator-card {
        padding: 2rem;
        gap: 2rem;
    }
    
    .options-grid {
        grid-template-columns: 1fr;
        gap: 1.2rem;
    }
    
    #password-display {
        font-size: 1.8rem;
        padding: 1rem 1.2rem;
    }
    
    .app-header h1 {
        font-size: 2.6rem;
    }
    
    .toast-container {
        bottom: 1.5rem;
        right: 1.5rem;
        left: 1.5rem;
    }
    
    .toast {
        width: 100%;
        justify-content: center;
    }
}